Electrical apparatus including one or more dry-plate rectifiers



May 14, 1957 MARTIN 2,792,537

ELECTRICAL APPARATUS INCLUDING ONE OR MORE DRY-PLATE RECTIFIERS Filed 001.. 28, 1953 2 Sheets-Sheet 1 May 14, 1957 H MARTIN 2,792,537

ELECTRICAL APPARA TUS INCLUDING ONE OR MORE DRY-PLATE RECTIFIERS 2 Sheets-Sheet 2 Filed Oct. 28, 1953 Fig- 7 Inventor:-

United States Patent ELECTRICAL APPARATUS mCLUDING ONE OR MORE DRY-PLATE RECTIFIERS Heinz Martin, Berlin-Neukolln, Germany, assignor to Siemens-Schuckertwerke Aktiengesellschaft, Berlin and Erlangen, Germany, a joint-stock company under German law Application October 28, 1953, Serial No. 388,851 Claims priority, application Germany November 3, 1952 8 Claims. (Cl. 317-234) My invention relates to an electrical apparatus including one or more-dry-plate rectifiers and, more particularly, to an apparatus of the type in which a stack of disk-shaped rectifier elements is encased in a hole of a supporting body consisting of a thermoplastic insulating material, such hole being covered by a terminal element, preferably by a' resilient contact strip, such terminal element being fixed to the supporting body.

In prior apparatus of such type the terminal element constituting a cover or a bottom plate for the hole was fixed to the supporting body by additional attaching means, such as a rivet or the like.

It is the object of the present invention to simplify the apparatus by elimination of such separate attaching means provided in addition to the body. It is another object of my invention to provide an apparatus of the character above defined which lends itself to easy manufac'ture and assembly and is reliable in operation and requires a minimum of material.

The invention further aims to reorganize the apparatus of the above described type in such a way as to'utilize the plasticity of the insulating material for the attachment of the terminal element to the supporting body to thereby eliminate the necessity of providing attaching elements of metal, such as rivets, screws or the like.

I attain these objects by providing the insulating body of a thermoplastic insulating material with integral projections which will engage the conductive terminal strip when the same has been placed on thebody-so as to cover the hole accommodating the dry-plate rectifier,- which projections are then rendered plastic and are so deformed as to extend over and engage an edge of the strip whereby the same is securely held in position. Preferably, the edge is the edge of a bore or hole in said strip. In such event, the integral projection of the supporting body is in form of a stud which may be deformed in the same manner as a rivet so asto receive a head extending over the strip. The integral projections are preferably provided on the supporting body when the same is manu factured, for instance molded from the thermoplastic ma terial. While I prefer to give such projections the shape of studs, they may have any other suitable shape. Preferably, the supporting body is provided with shouldersfor lateral engagement with the terminal strip, whereby the latter will be securely held in position against displacement on the body, said shoulders cooperating with the deformed projections to rigidly maintain the terminal member in position on the supporting body. The shoulders may be formed, for instance, by a recess provided on the body into which the terminal element may be placed. The latter may be so mounted on thesupporting body as to beheld on the body by thedeformed projections in a cantilever fashion, the free end of the terminal element covering the hole accommodating t he dry-platerectifier. Alternatively, it maybe pr'eferable under certain pircum; stancesto hold the terminal element in position by the deformed integral projections of the supportingbody-in; Such a manner that the strip has a. portion between its ends the strip will also function ice covering the hole being engaged by the deformed projections on either side of said hole. Also, the terminal strip is preferably biased into pressure contact with said stack, whereby the rectifier plates will be pressed upon each other by the terminal strip. Where a single terminal strip constitutes the cover or the bottom plate of a plurality of holes, each hole accommodating a stack of disk-shaped rectifier elements, it may be preferable to provide the terminal elements with a plurality of tongues. An embodiment in which the terminal strip is held on both sides of the hole is particularly adapted to be so designed that to mechanically reinforce the insulating supporting body should the same because of its shape be comparatively fragile. The terminal element will thus perform the additional function of a mechanical reinforcement of the support.

A number of embodiments of my invention are illustrated in the accompanying drawings in which Fig. l is a section of a supporting body adapted to accommodate a dry-plate rectifier and a pair of terminal strips indicated by dotted lines, the section being taken along the line I-I of Fig. 2;

Fig. 2 is the plan view of the supporting body shown in Fig. l;

v Fig. 3 is a plan view of the supporting body shown in Fig. 1, of the dry-plate rectifier and of the terminal strips mounted thereon;

- Fig. 3a is a sectional view of the device shown in Fig. 3, the section being taken along the line Illa-Illa of Fig. 3; 1 Fig. 4 is a plan view of a supporting body provided with four stacks of dry-plate rectifiers and two pairs of terminal strips;

Fig. 5 is a plan view of a supporting body provided with a row of dry-plate rectifiers and the associated terminal strips;

Fig. 5a is a sectional view of the device shown in Fig. 5, the section being taken along the line Va-Va of Fig. 5;

Fig. 6 is the bottom view of the supporting body shown in Fig. 5

Fig. 7 is a sectional view of another modification of the supporting body provided with a dry-plate rectifier and a pair of terminal strips, the section being taken along the line VIIVII of Fig. 8, and

-Fig. 8 is a plan view of the device shown in Fig. 7.

in Figs. 1 and 2 I have shown a supporting body in form of a substantially oval plate 1 consisting of a thermoplastic insulating material provided with a central hole 2 adapted to accommodate a stack of disk-shaped rectifier elements.- The upper face of the body is provided with a fiat recess 3, whereby a shoulder-will be formed, such shoulder being composed of a pair of opposed parallel sec- 1 tions 36 merging into a semi-circular section 37 surrounding the hole 2, said sections 36 terminating at outwardly extending-end section's'38 of the shoulder. Moreover, the body is formed with a projection 4 having the shape ofa stud. A terminal element, such as a metal strip 7, provided with an enlarged head 7 fitting the recess 3 and further provided with a suitable bore may be so placed on the body 1 into the recess 3 thereof that the stud 4- will project through the bore of the metal strip. Thereupon, the stud 4 may be heated to become plastic and may be then so deformed as to receive the shape of a rivet head 4a which extends overthe strip 7 and thereby holds the same in firm contact with the body 1. The shoulders 36 and 37 engaging the head portion 7' of the terminal element will'secure same on'the body against pivotal displacement. From the foregoing descrip{ Similarly, the bottomface. of body 1 is provided with that the rivet stud 4,-- 4a' constitutes an arenas? a flat recess 39 fhrming a shoulder similar to shoulder 36, 37, 38. While the recess 3 extends towards the right end of body 1, the recess 39 extends to the left end thereof. The body is provided with an integral stud projecting fromthe bottom face of recess 39 and adapted to engage a bore of a second terminal strip 6 which may be placed into recess 39 so as to constitute a bottom plate covering the hole 2. Thus, it will appear that the two recesses 3 and 39 provided at the top and at the bottom of the supporting body I extend to opposite ends being open at the respective end face of the body 1. Preferably, the body is molded with the studs 4 and 5 and with the recesses 3 and :39, for instance in an injection molding apparatus. By placing the terminal elements 6 and 7 into the recesses '3 and 39 on the top face and the bottom face of the body 1 slipping the terminal elements over the studs 4 and 5, the terminal elements will be brought into a position in which they are securely held against pivotal displacement. In assembling the device, the operator will first fix the bottom terminal '6 to the body 1 to thereby close the hole 2 at the bottom and will then place the stack of disk-shaped rectifier elements into the hole. Thereup-on he will place the terminal strip 7 in position to close the hole 2 at the top thereof. Subsequently, the two terminal strips will be riveted in position by a suitable deformation of the studs 4 and 5 shaping same so as to form integral rivet heads 4a thereon which extend over the strips 6 and 7.

Preferably, the terminal strips 6 and 7 are provided with dents 7a which project inwardly so as to contact the stack of. rectifier plates, such dents registering with the hole 2. In this manner, one or both of the contact strips 6 and 7 may be biasedinto pressure contact with the stack engaging the topmost or bottommost rectifier plate, one or both terminal strips constituting resilient elements which will compress the stack.

In the embodiment shown in Fig. 4, the supporting body 8 is provided with four holes located at the corners of a square, each of said holes accommodating a stack of dry rectifier plates, the four stacks constituting a full- Wave rectifier. Four terminal elements 9, 10, 17 and 18 are provided, each having a pair of tongues, such as 9a, 9b and 10a, 10b, cooperating with two of said rectifiers, each tongue extending over and covering one of the holes accommodating the stacks of rectifier plates. Each of the terminal strips is fixed to the supporting body 8 by means of a pair of integral studs 11 and 12, or 13 and 14 respectively, which project from the supporting body 8 and are deformed with rivet heads after the terminal strips have been slipped on the studs. supporting body 8 is provided with flat recesses, such as 15 and 16, conforming to the head portions of the contact strips 9 and 1.0. Therefore, in assembling the device the operator may simply place the terminal strips into the recesses as has been described in principle with reference to Fig. l. The bottom face of the supporting body 3 is provided with similar recesses for accommodation of the terminal strips 17 and 18 which are displaced by 90 with reference to the supporting plates 9 and 10 disposed at the top of the body. Therefore, each of the bottom strips 17 and 18 will cooperate with another pair of rectifier stacks than do the top terminals 9 and 10. it will be readily understood that the device shown in Fig. 4 is particularly adapted for a dry-plate rectifier of the Graetz type.

In the embodiment of my invention illustrated in Figs. 5 and 6 the body 19 is provided with a row of eleven equidistant holes, each accommodating one stack of rectifier plates. The top face of body 19 is provided with a plurality of flat recesses registering with such holes and opening towards the right hand side as viewed in Fig. 5 each recess being adapted to accommodate one terminal strip similar to strip 7 shown in Fig. 3. These terminal strips designated by 20, 21, 22, 23, 24, 25, 26, 27, 28,29 and 30 are held in position by studs 33 which Preferably, the

are integral with the body and project through bores of the terminal strips being shaped with rivet heads. Moreover, each terminal strip is provided with a dent 32 projecting into the respective hole for pressure contact with the dry-plate rectifier therein. The bottom of body 19 is provided with a singlelongitudinal recess 40 registering with the row of holes containing the dry rectifiers and equipped with a single terminal bar or strip 31 provided with dents 34 which register with the holesof body 19:

and project into the same to contact and exert pressure upon the rectifier stacks. Moreover, the body 19 is provided at its bottom with studs 35 extending through reg-' istering bores of strip 31, each stud 35 being located between a pair of rectifiers. As a result, the strip or bar 31 is rigidly connected to the body 19 over the entire length thereof and is thus adapted to reinforce the same against any possible fracture.

In the embodiments described hereinabove, each of the terminal strips 6, 7, 9, 10, 17, 18 and 20 to 30 is dis posed in cantilever fashion, the free end of the strip covering the hole contacting the dry-plate rectifier therein, the strip being engaged between its ends by the deformed integral fixture projection 4, 5, 11, 12, 13, 14, or

33 respectively. In other words, the free end of each of the contact strips constitutes a cover or bottom plate of the hole containing the rectifier.

In Figs. 7 and 8, however, I have shown another embodiment in which the strip has a portion between its ends covering the hole and contacting the rectifier, the body having at least two integral projections adjacent to and disposed on opposite sides of the hole for engagement with the strip. Thus, it will appear that the body 101 is molded with two cylindrical or conical studs on either side of hole 102, such studs registering with bores provided in the terminal strips and 106. The hole 102 provided in the body 101 contains a stack of rectifier plates 103 and a helical pressure spring 104 of metal which will compress the stack'establishing at the same time an electrical connection between the stack and the adjacent terminal strip 105. In this manner, a highly conductive contact between the individual rectifier disks and a highly conductive connection between the latter and the terminal strips 105 and 106 will be ensured. In assembling the device, the operator will slip the respective contact strip 105 or 106 over the cylindrical or conical studs 101a and 10111, or 1010 and 101d respectively, and will then deform such studs to provide same with rivet heads as shown in the illustration. An essential feature of the embodiment shown in Figs. 7 and 8 is the large contacting area between the terminal contact strips and the supporting body 101, whereby the strips will act as mechanical reinforcing elements for the body.

While I have described my invention with reference to a number of embodiments thereof, I wish it to be clearly understood that the same is in no way limited to the details of such embodiments, but is capable of numerous modifications within the scope of the appended claims.

- What I claim is:

1. In an electrical apparatus of the character described, the combination comprising a supporting body of' a thermoplastic insulating material having a hole and a projection adjacent thereto, a stack of disk-shaped rectifier elements disposed within said hole, and a conductive terminal strip mounted on said body so as to cover said hole, said projection being formed with an integral portegral portion engaging and extending over an edge of said strip to hold same in position.

2. The combination claimed in claim 1 in which said supporting body is provided with shoulders surrounding said hole and adapted to engage said strip to thereby secure same "on said body against pivotal displacement.

3. In an electrical apparatus of the character described, the combintion comprising a supporting body of a thermoplastic insulating material having a hole and a projecting stud adjacent thereto, a stack of disk-shaped rectifier elements disposed within said hole, and a conductive terminal strip mounted on said body so as to cover said hole and provided with a bore, said projecting stud extending through said bore, its end being formed with an integral rivet head extending over said strip to hold same in contact with said body.

4. The combination claimed in claim 3 in which said body is formed with shoulders engaging opposite edges of said strip to secure same against pivotal displacement.

5. The combination claimed in claim 1 in which said strip has a portion between its ends covering said hole, said body having at least two integral projections adjacent to and disposed on opposite sides of said hole for engagement with said strip.

In an electrical apparatus of the character described, the combination comprising a supporting body of thermoplastic insulating material having a plurality of holes, stacks of disk-shaped rectifier elements, each stack disposed in one of said holes, and a single conductive terminal strip mounted on said body so as to cover said holes, said supporting body being formed with integral projecting portions engaging and extending over edges of said strip to hold same in position.

7. A dry plate rectifier comprising a supporting body of thermoplastic insulating material having a hole and an integral projection adjacent said hole, a stack of planar rectifier elements disposed within said hole, and an elongated conductive terminal strip mounted on said body so that one end of said strip covers said hole and makes pressure contact with said stack of rectifier elements, said projection comprising a portion extending over an edge of said strip at an intermediate position along the length of said strip.

8. A dry plate rectifier comprising a supporting body of thermoplastic insulating material having opposed planar surfaces and a central opening extending from one surface to the other, a stack of planar rectifier elements disposed within said hole, each of said opposed planar surfaces being faced with a stifi planar metallic contact member enclosing said hole and contacting one end of said stack of rectifier elements, and a plurality of projections integral with said supporting body and extending over edge portions of each of said metallic contact members to fix them against said planar surfaces and thereby reinforce said supporting body.

References Cited in the file of this patent, UNITED STATES PATENTS 2,510,588 Kotterman June 6, 1950 

